1. Field of the Invention
This invention relates to a flexible amorphous silicon solar battery.
2. Description of the Prior Art
The amorphous silicon solar battery is a photoelectric conversion device wherein electron-hole pairs generated by photon energy at the potential barrier in an amorphous silicon thin film layer are accelerated by the electric field of its potential barrier and outputted as a current to be supplied to an external circuit. (Hereinafter, amorphous silicon will be called "a-Si".) Usually when the a-Si solar battery is put to practical use, a plurality of a-Si photoelectric conversion portions are connected in series with one another to increase the output voltage thereof.
The a-Si solar battery has the advantages that it can be produced at low cost and the surface area thereof can be easily extended. Therefore, in recent years, the developments and studies thereof have been actively conducted.
Conventionally, a flexible a-Si solar battery in which the a-Si thin film layer is deposited on a heat resistant organic film, is known.
However, this conventional a-Si solar battery employing a heat-resistant organic film as a substrate thereof has the following disadvantages relating to production thereof.
First, there is remarkable difference between the heat resistant organic film and a-Si deposited thereon in their coefficients of thermal expansion. Therefore, when the a-Si thin film layer is deposited on the heated organic film by means of a glow discharge decomposition method, spallings, cracks, and the like are liable to occur on the deposited layer.
Secondly, when the a-Si thin film layer is deposited on the heated organic film by means of a glow discharge decomposition method, gas is evolved from the organic film thereby to deteriorating the physical properties of the deposited a-Si thin film layer.